Insulation Resistance • Megger • Polarization Index • DAR • Temperature Normalization • IMD / Leakage Screening • Trend Diagnostics
Ship Insulation Resistance, Megger Test, Polarization Index & Electrical Leakage Tool
Screen insulation condition from timed DC resistance readings, calculate PI and DAR, normalize insulation resistance to a user-selected reference temperature, estimate test leakage current, and evaluate shipboard insulation-monitoring / earth-leakage conditions without inventing universal pass limits.
↑
De-energized insulation test only.
Confirm isolation, discharge stored energy, disconnect or protect sensitive electronics as required, use the correct OEM/test voltage, and prove the circuit dead before connecting an insulation tester. This tool does not authorize live testing.
IRTemperature-normalized resistance
PI / DARTime-resistance condition ratios
LeakageDC test-current equivalent
Timed Megger Test
V DC. Use the equipment/OEM-approved test level.
°C at test.
MΩ.
MΩ.
MΩ.
User-entered insulation correction factor. 1.0 disables temperature correction.
MΩ. Enter OEM/class/project criterion.
Set 0 when PI is not an applicable acceptance criterion.
Interpretation Basis
°C used for IR normalization.
User-entered factor. Generic factors are not universal.
Set 0 to make DAR informative only.
% drop in corrected 1-minute IR versus entered baseline.
Megger / PI Test Register
Use separate rows for phases, windings, feeders or equipment. PI can be made informative-only by entering 0 for the row's minimum PI.
| Use | Asset / phase | Type | Test V DC | Temp °C | R30 MΩ | R60 MΩ | R10 min MΩ | Min R1 @ ref MΩ | Min PI | Baseline R1 @ ref MΩ |
|---|
Shipboard Insulation Monitoring / Leakage Register
For unearthed / IT systems, measured insulation resistance and distributed capacitance are different contributors. The calculated capacitive first-fault current is an engineering estimate, not a touch-current certification.
| Use | System | Line voltage V | Frequency Hz | Measured R insulation kΩ | IMD alarm kΩ | Earth capacitance µF/phase |
|---|
Test & Safety Checks
Safety / compliance boundary: insulation testing can expose personnel and equipment to hazardous DC voltage and stored charge. Follow the vessel's electrical safety procedure, OEM instructions, class/flag requirements and tester manual. PI/DAR are diagnostic ratios, not universal proof of fitness. Online AC earth-fault current can include distributed capacitance and equipment filters that a DC resistance reading alone does not represent.